两种载荷下掘进机截割头转子系统动力学分析

为了研究不同截齿载荷条件下（锐利截齿和磨钝截齿）掘进机截割头和悬臂系统的动力学特性，建立了掘进机截割头-转子-轴承系统的弯扭耦合非线性动力学模型。考虑截割头和转轴之间的花键啮合间隙、滚动轴承接触的非线性因素影响下，推导了掘进机截割头转子系统的动力学微分方程。然后对受到时变载荷下的截割头转子系统动态响应特性进行了分析:在锐利截齿条件下，截割头转子系统在低转速n∈［15，20］时处于混沌和拟周期运动状态，提高转速后系统处于周期运动状态;在截齿磨钝条件下，截割头转子系统的振动明显加剧，混沌运动范围增大，频率幅值波动明显。结果表明：在给定截割煤层硬度、切削厚度等前提下，随着截割转速的升高，系统由混沌运动向周期运动转变。动态分析结果为掘进机的减振和动态设计提供了理论依据。

Dynamic Analysis of the Rotor System of the Cutting Head of the Roadheader Under Two Loads

n light of the dynamic characteristics of the cutting head and cantilever system of the roadheader under different pick loads (sharp picks and blunt picks), the bending-torsional coupling nonlinear dynamic model of the cutting head-rotor-bearing system of the roadheader is established. Considering the spline meshing clearance between the cutting head and the rotating shaft, and the nonlinear factor of the rolling bearing contact, the dynamic differential equations of the cutting head rotor system of the roadheader are derived. Then, the dynamic response characteristics of the cutting head rotor system under time-varying load are analyzed. The results show that under the condition of sharp picking, the cutting head rotor system is in chaotic and quasi-periodic motion state at low speed between 15 and 20, and the system is in periodic motion after the speed is increased. While the picks are blunt, the vibration of the cutting head rotor system is obviously aggravated, the chaotic motion range is increased, and the frequency amplitude fluctuates significantly. The system changes from chaotic motion to periodic motion with the increase of cutting speed at the given premise of cutting coal seam hardness and cutting thickness. The dynamic analysis results provide a theoretical basis for the vibration reduction and dynamic design of the roadheader.